They added a couple maps, but it's not enough to keep people interested. I'm surprised there are people with 300-400 games. One badass I played with on gold has 400 games and scored 100k points in the 9 rounds we survived. I'm at 80 games and still enjoy it enough but can't see how people play it that long. Pretty much you just keep playing so you can buy packs and hope for the best weapons and perks.
Agreed about the higher levels, you can't do much but stay in cover and snipe. You basically have to play infiltrator if you want to be able to move freely at all.